Rachel Bilson and Jaime King celebrated their new CW drama, “Hart of Dixie,” with a raucous dance party at tiki bar Riff Raff’s Thursday night after the CW upfronts earlier that day. The duo toasted their new show “dancing up a storm” with fellow cast members and friends. “They were in the center of the dance floor with friends, showing off their moves,” said an onlooker. “Hart of Dixie” centers around a young New York doctor (Bilson) who takes over an Alabama medical practice.